Method of dyeing aluminum-modified polpropylene fibers with monoazodye

ABSTRACT

Method of dyeing metal-modified polyolefin fibers, which comprises applying a monoazo dye of the formula   TO METAL-MODIFIED POLYOLEFIN FIBERS.

' United States Patent Yutaka llosoda Tokyo, Japan June 28, 1968 Nov 2,I971 Mitsni Ka aln| Kogyo Kabnshiki Kalsha (Mltsui Chemical IndustryCo., Ltd.) Chuo-ku, Toky i Jlpln Inventor Appl. No. Filed PatentedAssignee METHOD OF DYIZING ALUMINUM-MODIFIED POLPROPYLENB FIBERS WITIIMONOAZODYE 2 Claims, No Drawings {56] References Cited UNITED STATESPATENTS 3,257,379 6/1966 May etal. 8/42 X 3.389.956 6/l968 Mohr et al.8/42 Primary Examiner-George F. Lesmes Assistant Examiner Patricia C.Ives Attorney-Wenderoth, Lind & Ponack ABSTRACT: Method of dyeingmetal-modified polyolefin fibers. which comprises applying a monoazo dyeof the formula to metal-modified polyolefin fibers.

This invention relates to a method of dyeing metal-modified fibers withvarious monoazo dyes formed by coupling 5- aminosalicyclic acid orS-amino-o-cresotinic acid, which is used as the diazo component, withvarious compounds having hydroxyl groups. As the result we discovered asurprising fact polyolefin fibers with a monoazo dye which can beexpressed 5 that the monoazo dye of the formula 1, which is obtained byy a'fol'mula coupling S-amino-o-cresotinic acid with p-cresol; exhibitsexcellent ability to dye the fibers clear and pure yellow, and that OHthe light fastness of the color is of the highest grade. We H000furthermore discovered that only-the specified monoazo dye HO couldachieve all of the foregoing objects. That is, the clear color tone canbe satisfactorily obtained with the monoazo H 0 B dyes formed bycoupling S-aminosalicyclic acids with acetani- 3 lides, but the colorexhibits extremely low light fastness. l 5 Neither the homologues noranalogues of the structure of for- The object of the invention is toprovide a method of dyeing mula 1 show the excellent effect of the dyeof this invention. metal modified polyolefin fibers, particularlyaluminum- His statement is substantiated by table 1 below, which givesmodified polypropylene fibers, yellow of brightness and fasttheexperimental results of dyeability of aluminum-modified n polypropylenefibers with the dyes synthesized from diazo As a means to improve thepoor dye affinity of components and coupling components selected fromclose polypropylene fibers, a process has been proposed in whichanalogues of the specified components of-the subject dye.chelate-forming metal salts such as fatty acid salts of alu- From thesame table, it can be clearly understood that when minum, nickel, zinc,etc. are incorporated with polypropylene the coupling component has anyconventional substituent in fibers toform dyeable metal-modifiedpolypropylene fibers. the art, such as'halogen, long chain alkyl,substituted amino and thereafter the fibers are dyed with such dyestuffswhich 2 group, etc. on its benzene ring, the resultant monoazo dyesexcan form chelate ring with the above metals. However, itis by hibitinferior dyeing effect. Also when the coupling comno means easy to findsatisfactory dyes for all colors. Particuponent has a methyl group atortho or metaposition to the larly dyeing of aluminum-modified fibersbright, fast and pure hydroxyl group, or has a methyl group atorthoposition besides yellow has been regarded very difficult. that atparaposition, neither the resultant dyes possess We have experimented ondyeability of aluminum-modified equivalent dyeing properties to thoseofthe subject dye.

TABLE 1 D eing abilit for alui nlnum-mo ified polypropylene fibersDyeing 1 Light properfastness 2 ties in of dyed Coupling 100 0. goodDlazo component component dyeing (class) Compounds of the invention HOOCHO l l HO-QNHt H? A 4 C2H5 H? A-X Hull A 1 G (3113 X Analogouscompounds; H0O(|J H(|) (llH A-() 5 E CH3 HO A TABLE 1 Dyeing ability foraluminum-modified polypropylene fibers Dyeing 1 Light properiastness 2ties in of dyed Coupling 100 C. good Diazo component component dyeing(class) I E 1O2 O l C Analogous compounds H 0 Off H(|) A-O 3-4 Q CH5CiHnfli) Note. Excellent; O= Satisfactory; A= Poor; X=Very poor.

2 Measured in accordance with J IS L-1044 (1959).

The dyestuff of this invention can dye nickelor zincmodifiedpolypropylene fibers yellow, with the light fastness of, respectively,7-8 and 6, although the hue was not quite as clear as that onaluminum-modified polypropylene fibers.

The dye of the formula l is prepared by diazotizing 5-amino-o-cresotinic acid, and coupling the same with p-cresol. Forexample, a simple method will comprise diazotizing 5- amino-o-cresotinicacid in the accepted manner, neutralizing the excessive mineral acid,mixing with sodium salt solution of p-cresol, and stirring the mixturefor a prolonged period until all the diazo component is consumed. Theproduct dye is precipitated form the reaction liquid in the form ofsodium salt, which can be separated by filtration. If desired, theprecipitate so separated may be dissolved or suspended in water andobtained in the form of free acid after acidifying the system. The dyethus obtained by filtration can be ground with a dispersing agent to beconverted to a disperse dye.

Incidentally, the dye of the formula I may appear to be obtainable alsoby coupling Z-amino-p-cresol with o-cresotinic acid, but it isimpossible to obtain the dye by such method.

The invention will be explained in further details by way of thefollowing Examples.

EXAMPLE I 16.7 Grams of S-amino-o-cresotinic acid were dissolved in l 1cc. of 36.5 percent hydrochloric acid and 200 cc. of water. into thesolution then 20 cc. of 5N sodium nitrite solution was dropped at 5 C.,followed by 2 hours stirring. The excessive hydrochloric acid wasneutralized with sodium carbonate solution, and the system was added toa solution consisting of 20 g. of p-cresol, 10 g. of caustic soda and200 cc. of water, at 5-7 C. After 5 hours stirring, the system was letstand overnight. Whereupon the object dyestuff was precipitated in theform of yellowish brown sodium salt. Tl'le precipitate was filtered andwashed with a minor quantity of water. The cake was suspended in 400 cc.of water, heated and dissolved under addition of caustic soda. To thesolution then hydrochloric acid was added to precipitate the dye as afree acid. The precipitate was filtered, washed with water and dried toyield 20 g. ofa pure dyestuff.

The thus-refined dye was a yellow crystalline material having a meltingpoint of 240 C., which was soluble in conc. sulfuric acid, giving a redsolution. The dye was also soluble in aqueous caustic soda in red color.The results of its elementary analysis were as follows:

Calculated values ('1) (12.94 4.90 9,79

Measured values ("1) blbl 513 9.53

A disperse dye was formed from the above product by the steps of addingsodium dinaphthyl-methanesulfonatc to the dye cake before drying, in aquantity of twice the dyestuff, grinding the mixture and drying thesame. The disperse dye contained approximately 33 percent ofthe monoazodye.

Separately, reversal of the foregoing coupling was experimented on thescale of 0.1 mol gram. That is, diazotized oamino-p-cresol was added toan alkali solution of o-cresotinic acid, performing the coupling in theconventional manner. The resultant precipitate was filtered and dried toyield l l g. of a dyestuff. The dye was dark brown powder, soluble inconc. sulfuric acid in brown color, and also in caustic soda solution,in reddish brown color. The product dyed aluminium-modifiedpolypropylene fibers in not yellow but light reddish brown color, havinga poor light fastness.

EXAMPLE 2 0.3 gram of the so obtained finely powdered dye was dispersedin 500 cc. of water, to which were added 0.25 gram of anonionic'surfactant prepared from nonyl phenol and ethylene oxide and0.2 cc. of acetic acid of 6 Be to prepare the dye bath. 10 grams ofmodified polypropylene containing 0.2 percent by weight of aluminum(basic aluminum stearate was incorporated) were dipped in this dye bath,which was then raised to the boil. The dyeing was carried out for onehour, followed by water-washing of the dyed fibers. The fibers were thenheated for 20 minutes at 85 C. in 500 cc. of water in which had beendissolved 0.25 gram of Monogen" (sulfates of higher alcohol; registeredtrade name of Daiichi Kogyo Company, Japan), 0.5 gram of caustic sodaand 0.5 gram of sodium hydrosulfite, followed by washing with water.

. The dyedproduct so obtained exhibited a very brilliant yellow color,and its light fastnesses was 7-8, and drycleaning, nitrogen oxide gas,washing and rubbing were in all cases a rating offive. It was also fastto sublimation.

EXAMPLE 3 The dyeing of example 2 was repeated except that the fibersAto aluminum-modified polypropylene fibers.

2. A method according to claim 1 wherein the monoazo dye is applied tothe aluminum-modified polypropylene fibers in an aqueous medium.

2. A method according to claim 1 wherein the monoazo dye is applied tothe aluminum-modified polypropylene fibers in an aqueous medium.